/*
 * Copyright 2007 ETH Zurich
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 *
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 */

package org.llrp.ltk.net;

import org.apache.mina.core.buffer.IoBuffer;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.filter.codec.ProtocolEncoder;
import org.apache.mina.filter.codec.ProtocolEncoderOutput;
import org.llrp.ltk.exceptions.InvalidLLRPMessageException;
import org.llrp.ltk.types.LLRPMessage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * LLRPBinaryEncoder encodes LLRPMessage objects to the LLRP binary format.
 */

public class LLRPBinaryEncoder implements ProtocolEncoder {

    Logger log = LoggerFactory.getLogger(LLRPBinaryEncoder.class);

    public void dispose(IoSession session) throws Exception {
        // nothing to dispose
    }

    /**
     * convert LLRPMessage object to binary format
     */

    public void encode(IoSession session, Object message,
                       ProtocolEncoderOutput out) throws Exception {
        LLRPMessage llrp = (LLRPMessage) message;
        log.debug("encoding message " + llrp.getClass());
        byte[] byteMsg;
        try {
            byteMsg = llrp.encodeBinary();
        } catch (InvalidLLRPMessageException me) {
            log.warn("no message written because error occured: "
                    + me.getMessage());
            return;
        }
        // Note: ByteBuffer is renamed in MINA to IOBuffer
        IoBuffer buffer = IoBuffer.allocate(byteMsg.length, false);
        buffer.put(byteMsg);
        buffer.flip();
        out.write(buffer);
    }

}
